A Republican senator has deplored the Obama administration for using taxpayer funds to advertise the upcoming implementation of the Affordable Care Act, the president’s signature health care overhaul.

The Health and Human Services Department, through the Centers for Medicare and Medicaid Services, plans to spend $8.7 million to “promote Obamacare through advertising across the country,” Sen. Marco Rubio, R-Fla., wrote in a letter to HHS Secretary Kathleen Sebelius.

“This blatant misuse of federal dollars to promote a fundamentally flawed law is extremely concerning, especially considering the extensive unknowns surrounding the coming launch and implementation of Obamacare,” Rubio said.

The health insurance marketplace -- a key provision of the health care overhaul allowing eligible individuals, families and small business owners to shop for insurance plans -- will open Oct. 1.

“Starting Oct. 1, millions of Americans will be able to access quality, affordable health coverage for the first time, and we will continue educating and informing the uninsured of this opportunity,” HHS spokeswoman Joanne Peters said.

HHS -- which would not confirm the funding set aside for the campaign -- already runs television ads annually during Medicare open enrollment. The agency will begin its marketplace ads in October and has contracted Weber Shandwick, a public relations firm, to help run its outreach campaign

Rubio rejected the notion the ads had potential value, stating the campaign resulted in “misappropriating public funds in an effort to sell bad ideas to good people.”